Added Header and Footer support using Skia

printing/units.h

Index: printing/units.h
diff --git a/printing/units.h b/printing/units.h
index cc6124101c6c134f0acdd57764a0cdbe1d9e5d0c..bd6d67a74d6fa430497dfc62981cbd57f58b8b25 100644
--- a/printing/units.h
+++ b/printing/units.h
@@ -36,6 +36,13 @@ int ConvertPixelsToPoint(int pixels);
 // Converts from 1 pixel to 1 point using doubles.
 double ConvertPixelsToPointDouble(double pixels);
 
+// Converts from 1 point to 1 pixel using doubles.
+double ConvertPointsToPixelDouble(double points);
+
+// Splits the horizontal width equally into segments with an interstice
+// between each segment. Returns the width of a segment.
+double GetHeaderFooterSegmentWidth(double page_width);
+
 }  // namespace printing
 
 #endif  // PRINTING_UNITS_H_